1. Field Of The Invention
The present invention relates to visual warning systems for use with locomotives and particularly to parameter-sensitive controls for the visual warning systems used.
2. Prior Art
U.S. Pat. No. 4,213,115 and others teach the art of visual warning systems for use on locomotives to warn pedestrians and vehicular traffic at highway grade crossings of the approach of a moving train. In each of these prior systems, a light is actuated whenever the engineer takes some action which is associated with the approach to the crossing, e.g., blowing the horn or ringing the bell.
The contemporary use of high intensity strobe lights, or "ditch lights", for illuminating and/or warning the approach area of a highway/rail crossing has a detrimental effect on the normal operation of the locomotive in slow-speed switching moves. The same actions taken by the locomotive engineer to warn motorists of the approach of the train are frequently performed while the locomotive is stopping, starting, and changing directions of movement. The visual warning lights of such prior art systems are thus actuated during these conditions. Each of these activities are performed while the engineer has a crew member on the ground to throw switches, guide the movement of the locomotive, or re-board the locomotive while it is accelerating. Unfortunately, the high intensity light may create a safety hazard through an unintended ability to blind and/or mesmerize the crew-member, who is standing in the exact centroid of the light beam.
Also, the effective use of the visual warning system may be nullified if a means for disabling the lights is provided which could inadvertently be left disengaged by the locomotive engineer. This could happen if a simple manual on/off switch were provided, for example, and would not be an effective fail safe way of alleviating the problem.